Fastest part of disk?

[mkhs]

Which part of the hard disk is the fastest? As I understand it, a hard disk writes from the center of the platter outward to the edge. I always thought the closer to the center, the faster it would be. However, when burning CDs, the outer tracks appear to be far faster. Would this be true of hard drives as well?

and how is data stored if there are multiple platters? I'm wondering because I want to know which partition (first or last) would be the fastest.

[Leadman584]

First part of disk, definitely faster. I've been using 10GB partitions at beginning of Drive. Since I've managed to destroy another OS install (first time it wasn't my fault), I'm looking at perhaps an 8GB partition. Run HDTac, or HDTune, and note performance characteristics. Last 10-20% of any drive will have lower performance. Not really true with RAID5 for some reason. Of course, I'm using 5 small drives, instead of one big one.

Sticky post from IceCzar has links to comprehensive articles on platter geometry. If these aren't confusing enough for ya, read the RAID related links, took me over 5 hours to read through the first time, and I still got a ways to go.

[Paragon]

I always heard and was told that the first partition you make will be at the center of the platter. The last will be the outer. This from talking with someone at Hitachi/IBM.

Outer area will be faster.

[Leadman584]

Outermost area is most prime real estate, grabbed by MBR at OS install. If you can keep OS, apps, and swap within first 10% of drive capacity good results are likely, not guaranteed. Defective drives, installs, and drivers can make this untrue, regardless of what part of the HD you use.

[KevC]

The reason the outer parts of the CD are faster (as i understand it) is because the drive can spin it faster. Less movement of the head aswell.

[mkhs]

http://www.pcworld.com/howto/graphics/73826-2002p152-1b.jpg

This picture seems to suggest that hard drives write from the outer tracks in towards the center :confused:

[M11]

Drives spin at a constant RPM. But different parts of the disk will travel at different speeds. The outside moves faster than the inside as at any sampled point, the radius is greater, thus leading to a greater circumference. The speed increase can be inferred by looking at the following equations.

C=2(pi)*r
tan. velocity=RPM*r

With a higher speed, the inside is related to the outside as 5400RPM is related to 7200RPM (not in exact proportions).

[stevewm]

http://www.pcworld.com/howto/graphics/73826-2002p152-1b.jpg

This picture seems to suggest that hard drives write from the outer tracks in towards the center :confused:


Thats correct...

Hardrives write from the outer tracks to the inner tracks. They have always been this way. Simply because its faster on the outer edges of he platter. A program like HDTach easily demonstrates this. It will show you the speed differences....

CDs/DVDs on the otherhand are written from the inner edge to the outer edge....

[Paragon]

Yeah.. it seems I was misinformed.. Nero has a nice drive speed tester that will test seperate partitions [found when making an image] and of course my swap partition is slow.. oh well. Need to format soon anyhoo.

[acascianelli]

when i run hdtach on my system here at work running a ide 7200rpm 40gb drive, the performance is even till about the 28gb mark then it starts falling from 30mb/s to about 23 mb/s.